मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Explain briefly: PCR - Biology

Advertisements
Advertisements

प्रश्न

Explain briefly:

PCR

स्पष्ट करा
Advertisements

उत्तर

PCR (Polymerase Chain Reaction) is a technique used to create multiple copies of a specific DNA segment in vitro. It amplifies DNA by repeated cycles of three steps:

  1. Denaturation: Heating the double-stranded DNA to around 94°C to separate it into single strands.
  2. Annealing: Cooling to 46-60°C to allow short primers to bind to complementary sequences on the single-stranded DNA.
  3. Extension: Raising the temperature to about 72°C so a heat-stable DNA polymerase (Taq polymerase) synthesizes new complementary strands, duplicating the target DNA.

Repeating these cycles exponentially amplifies the DNA segment, producing millions of copies rapidly. PCR is widely used for DNA amplification, genetic fingerprinting, disease detection, DNA sequencing, and molecular mapping. It was introduced by Kary Mullis in 1985 and relies on the thermostable enzyme from Thermus aquaticus to function at high temperatures without being denatured.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 13: Principles and Processes of Biotechnology - NCERT EXERCISES WITH ANSWERS [पृष्ठ ५३६]

APPEARS IN

नूतन Biology [English] Class 12 ISC
पाठ 13 Principles and Processes of Biotechnology
NCERT EXERCISES WITH ANSWERS | Q 10. (a) | पृष्ठ ५३६

संबंधित प्रश्‍न

Name two commonly used bioreactors.


Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.


Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?


Can you recall meiosis and indicate at what stage recombinant DNA is made?


Describe briefly the following:

Bioreactors


State the importance of using a bioreactor.


Prepare a flow chart in formation of recombinant DNA by the action of restriction endonuclease enzyme EcoRI.


Answer the following question:
Describe the formation of recombinant DNA by the action of EcoRI.


Which of the following term used for defining a viral genome incorporated into host DNA?


______ plays an important role in blood clotting.


DNA fragments generated by the restriction endonuclease in a chemical reaction can be separated by ______.


Gene Amplification using primers can be done by ______.


Blood stains are found at the site of a murder. It DNA profiling technique is to be used for identifying the criminals, which of the following is ideal for use?


The first step in recombinant DNA technology is


In addition to the Taq polymerase enzyme, which other thermostable DNA polymerases have been isolated to be used in PCR?


In PCR, primers are used for ______.


An antibiotic resistance gene in a vector usually helps in the selection of ______.


Which of the following steps are catalysed by Taq DNA polymerase in a PCR reaction?


A bacterial cell was transformed with a recombinant DNA molecule that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be ______.


Which of the following should be chosen for best yield if one were to produce a recombinant protein in large amounts?


How is copy number of the plasmid vector related to yield of recombinant protein?


Identify and explain steps ‘A’, ‘B’ and ‘C’ in the PCR diagram given below.


Read the following paragraph and answer the questions that follow:

Biotechnology revolves around the "gene of interest", with an objective to open various avenues for human welfare in health, medicine, pharma, agriculture etc. using different techniques, tools and processes. One of the breakthroughs of biotechnology in medicine is the gene therapy.
  1. Name the human disease for which the gene therapy was used for the first time.
  2. Explain the steps of gene therapy carried to cure the disease using the lymphocytes of the patient. Why is this therapy not a permanent cure of the disease?
  3. Write the possible permanent cure of the disease by the gene therapy that is in progress. 

Assertion (A): Synthetic oligonucleotide polymers are used during Annealing in a PCR.

Reason (R): The primers bind to the double stranded DNA at their complementary regions.


Write the scientific name of the source organism of the thermostable DNA polymerase used in PCR.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×